Reversible flow fan



June 21, 1955 E. R. TROXELL, JR 2,711,283

REVERSIBLE FLOW FAN Filed May 20', 1950 INVENTOR wzmag ATTORNEY EDGARR.T2oxan.1.,JR.

REVERSIBLE FLOW FAN Edgar R. Troxell, Jr., Bronxville, N. Y. ApplicationMay 20, 1950, Serial No. 163,286 3 Claims. Cl. 230-42) My inventionrelates to means and method of room ventilation and particularly asapplied to overhead window ventilators for ofiices, although .generallyadaptable to any window, transom, doorway or other suitableopening.

At present in most spaces having double hung windows,

ventilation is attempted by raising the lower sash a short distance,with or without a so-called window guard. Such opening, being in or nearthe breathing zone, is neither the properlevel at which to admit outdoorair, except perhaps in warm weather, nor, at any time, the level atwhich smoke, odors and vitiated air can best be expelled. As is wellknown, this method is dependent upon outside wind pressure which, indifferent directions, either causes draftsfrom the crack opened betweenthe upper and lower sashes, as well as the opening itself, or draws airout at these points. In the latter case, the replacement air may comefrom an unsatisfactory source and a large amount of heat be lostwithoutproducing the desired ventilation of the space. In any case, this methodis fundamentally unsound in principle as it (1) causes drafts in coldweather, (2) leaves a blanket of warm, vitiated air pocketed above theopenings, and (3) lacks definite control. 7 p p Means and method,according to my invention, are primarily for positive, winterventilation although adaptable also for summer ventilation as well asfor distributing and diffusing conditioned air.. The primary action ofmy device is to draw in, mechanically, a controllable amount ofuntempered outdoor air and spread it horizontally in a fan shapedstratum or spray near the ceiling of the space served. At the same time,by mechanical means as well as by induction,-to spread a similar,separate stratum or spray or blanket of room air immediately under thestratum of outside air. If the upper stratum is colder, and henceheavier, than the underneath stratum of room air, the former must and'will fall and, in so doing, commingle and diffuse with-the room airbefore reaching the breathing zone.

It is emphasized that by the use of the means and method of my inventionthe introduction of air at a lower temperature than that of the room orspace served, is made positive and controllable and that its action, byblanketing the colder. air introduced, with a separate stratum of warmerairunderneath, prevents the colder air falling before being completelycommingled and 'diffused withthe room air. Also that thefluse of mydevice, by drawing in a controllable quantity of outdoor air andprojecting it, at controllable velocity,in a fan shaped stratum or sprayin a horizontal direction near the ceiling of the space served, giveswide distribution and thorough diffusion of the air used forventilation.

In such spaces as this device is designed to serve, it may be desirableat times to exhaust heat, smoke, odors or vitiated air from the upperstrata of said space. As a matter of fact, alternating supply andexhaust action may well be found the most satisfactory method ofsecuring desired results, particularly in warm weather when otherwindows are open but when there is little or no nited States Patentsmoke, odors etc.

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natural'air movement. To that end, in this device according to myinvention, a revolvable inner fan-housing, manually turned to its Ialternate positions, accomplishes this complete reversal of airmovement," viz., supply or exhaust. To accomplish these results, Iprovide a motordriven, double disk-type centrifugal fan in a suitabletwoway housing, fastened to a conditioned airduct oradjacent the, top ofa window which is opened sufficie'ntly for the purpose. A revolvableinner fan-housing, in o ie position, provides discharge of air drawnfrom outside, either from a duct or from outdoors, as the case may be,

into the room in a fan shaped stratum. Simultaneously,

it provides for discharge of a similar separate fan shaped stratum ofroom air immediately under the first mentionedstream. v a Q Thus adevice according to my invention' provides (1) means for introducingartificially chilledair or untempered outside air into a space withoutdrafts, (2) utilization, in cold weather, of waste heat which otherwisestratifies at the top. of a room, (3) more uniform heat distribution ina space, and (4) thorough distribution and diffusion of the air used forventilation; V

When the revolvable inner fan housing is manually turned to itsalternate position, air fromthe. top of the room is positively exhaustedoutdoors when the .device is properly arranged at the top of a window,to remove A device ofmy invention comprises-an outer flat, boxlikehousing, a motor of controllable speed-a'flixed thereto having a shaftextending vertically into the'housing, a centrifugal fan mounted on saidshaft, said fan having a central separationdisk at right angles to themotor shaft, with blades mounted thereon, above jand below said disk, soas to provide two separate streams or stratums of'discharged air, oneabove'the other, and permitt n two separate intakes to said blades, onefrom-above and the other from below thefan disk.

Within said outside housing is an inner housingcomprising asemi-circular member surroundingapproximately one-half of the peripheryof said fan, and revolvable through 1.80 degrees to provide either (1.)dischargeof air from both sets of blades into the room. or -(2)discharge of air from both sets of blades through a portion of theoutside housing into the'outdoor air. In both instances, the lower setof fan blades draws air from the upper part of the room through a.grille forming a part of the lower face of the fan housing. Intaketo theupper. set of fan blades is determined by alsecondsemicircular member ofthe revolvable inner fan housing. This portion is fixed to butdiametrically opposite the first named member and extends verticallybetweena plane near the top of the upperfanblades and the topplate ofthe outer housing. f i e p The'fun ction of the inner housing is suchthat, in one position, it causes bothsets of fan blades to discharge airinto the room, the upper'blades drawingv airthrough a portion of theoutside housing from outside. ,Manually effective means and method forthe. ventilation of small I ofiices and other rooms having outsidewindows.

A further object is to provide positive controlled ventilation withoutdraftsusing tempered 'or. untemperedtor outdoor air.

. Another object of the present invention istoprovide a centrifugal fancontained in a two way, two part housing.

one part of which housing is revolvable within the other to regulate andcontrol the direction of intake and of disr I V 3 charge of airby'thefan for the purpose of either supply or'exnaust of air.

Still another object is to provide means whereby outside air projectedinto a space by the fan may be blanketed l ath'f'ro'ri'ithe livingzoneof said space with a sepanargeb thefan, "of'air taken from the top ofthe jlf, th 'erebylforciiig'the outside air to conimin gle' th paceairbefo're'reaching'the breathing zone of the A Astillfurther object ofmy invention is to' provide a fan andhoils ing" there'for'such thatoutside tempered or undairdischarged int'o'a space may be raised intemre'bywaste heat otherwise Stratified in the upper "of the space'its'elf'a'nd commi'ngled with space air teachin the breathing 'zone orthe space. the foregoing and other objects in view, as will betjtojthjose'i'skilled in the artas thedescription proceeds, my inventionresides in the combination and arrangement of parts and in the detailsof construction dfintlie specificationand particularly pointed out I'peiided claims, it be'ing'underst'ood thatchanges' in theparticulembodiment of my invention may be made within"the1 scopeof what isclaimed without departing fromjthe spirit of theiuvention. I intend nolimitation otiferthan those of'the claims when fairly interpreted in thelight of the full disclosure and the present state of the art.

"Referring now' to the accompanying drawing illustrativeof a'pref'erredembodiment of my invention,

Fig. I is a sectional side elevational view showing a form of ventilatorarranged to draw in' 'and disassemfside air;'Fi'g. 2 is asectional viewsimilar to Fig. l with thsame ventilator arrangedto exhaust inside air;Fig. 3 is a perspective sketch illustrative of the inner revolvablehousing; Fig. 4 is a side elevation of the part shown in Fig. 3; Fig. 5is a bottom view of the fan housing, with motor removed; Fig; 6'isa'fragmentary top view showing thefan air cut-'ofi operable on exhaustoperation; Fig. 7 illustrates in elevation a complete windowinstallation viewed from the space served. 7

Similar reference numeralsrefer to similar parts in the s ra ,v cw

"Turning now to Figs. 1 and 2, a motor 19 is arranged to drive acentrifugal fan 9 having a central disk 8 and positioned withina flatboxlike' housing 7 open at both ends, 'on the'lowerfside of which areair inlet openings 6, 6 (Fig. 5). Within the housing 7is an innercircular re-. volvable housing 5 contained and guided in part by theturned-in lips 4 of the top and bottom plates of housing 7 and in partby a pivot 19' extending through the top plate "t h usin 7 f i Thisinner housing comprises two diametrically opposite semi-circular bandsor rings 2 and 3, open top and bottom,the' upper band 2 being axiallyoffset from the lowerband 3, said lower band so arranged as to partiallyencircle the periphery of fan 9 so as to direct the fan discharge asdesired and the upper band 2 arranged to determinefrom which directionthe air flows to the upper fan blades. A stiffening member 11 isprovided across the diameter of the revolvable housing 5. An operatinghandle 12, whereby the housing 5 may be revolved 180 degrees, extendsfrom the two bands through the outer housing 7 as indicated (Fig. 5 Afurther stitfening member lies across the open ends of band 2 providinga member through which the pivot 19 passes.

The outer housing 7 has a vertical dimension greater than the width ofthe fan, preferably twice the fan width, the intake space 13 above theplane of the top face of the fan arranged for flow of air from eitherend of the housing to the upper face of the fan. In operation, the upperband 7 or baflle is positioned either to seal off space 13 from the roomair (Fig. l) and open it to pass outside air or (Fig. 2) to seal offspace -13 from the outside air and open it to pass room air to fan 9. Atthe same time, the diametrically opposite lower band 3 completes theenclosure of fan 9 in such way as to open the fan discharge to the areasealed off from intake by the upper band 2, as clearly indicated inFigs. 1 and 2.

Preferably, for window ventilation, the outer housing is supported aswith screws 14, 14 to theppper part of the window casing 15. Telescopingside closure strips 18, 18 (Pig. 7) are provided, affixed -aswingmembers to the housing 7, the upper sash 16 being lowered andweather strips 17seal any cracks thus formed. 0

Preferably, also, the lower plate 1 of the outer fan housing 7, to whichmotor 10 is afiixed, is a separate cast or stamped member or grille or aportion of it is so constructed, thus providing a separate removablesub-assembly comprising grille, motor and fan. It will be noted that for"greater discharge efficiency of the fan when the ventilating deviceisacting to exhaust air from the space served (Fig. 2),"a cut-cit 21(shown in Fig.6) is provided within the' housing 7,'the edge of thehousing or the edge. of band 3 acting as a cut-off when discharge is tothe space.

Wh'atIclaim is: l l i 1. A ventilator comprising a housing having top,bottom and end portions,'driving nieans mounted on saidhousing andhaving a rotatable shaft projecting thereinto, a centrifugal impellerhaving blades and mounted on said shaft within said housing, a solid'disc forming a part of said impeller bisecting each blade and dividingthe impeller into upper and lower substantially identical sections, saidhousing including an opening in each or the opposite end portionsthereof, baflie means for said openings disposed within said housing andmovable about'the axis of said shaft and means to operate said baffiemeans whereby alternate upper and lower portions of said openings areopen or closed by said bafiie means, said upper portions to flow offluid to said impeller and said. lower portionsto tangential flow offluid from said impeller.

2. A device according to claim 1 wherein said impeller has a centralintake above and below said disc and has an axial width of'subst'antially one-half that of the casing measured between the top andbottom portions.

3. A device according toclaim 1 wherein said baffle means comprises twosemi-cylindrical portions disposed one above the other and joined attheir open ends, the lower portion of which is of substantially the samewidth as sa impe Refferences Cited'in the file of this patent UNIT EDSTATES PATENTS 336,194 Graves etalt- Mar. 2, 1886 929,767 Hubbard Aug.3, 1909 1,019,818 McMurdie r 'Mar. 12, 1912 1,055,487 Papin Mar. 11,1913 1,554,914 Guthier Sept. 22, 1925 1,937,483 Shurtlefi Nov. 28, 19-332,185,614 Whitfield Jan. 2,-1940 2,205,902 McMahan June 25, 19402,265,317 'Schlirf Dec. 9, 1941 2,337,325 Hach Dec. 21, 1943 2,363,191Miller Nov. 21, 1944 2,373,496 Paiste Apr. 1-0, 1945 2,373,497 PaisteApr. 10, 1945 2,398,627 Disbro' et al.- Apr. 16, 1946 2,523,933 Akesteret a1 Sept. 26, 1950 2,525,395 Boemer Oct. 10, 1-950 FOREIGN PATENTS190,492 Switzerland Apr. 30, 1937 596,328 Great Britain Jan. 1,

